Containers such as returnable bottles are handled a great number of times during manufacture, inspection, filling, shipping, washing etc. During such handling the bottles come into contact with various mechanical devices such as conveyors, inspection devices, other containers (such as bottles, jars, and the like), and surfaces such as boxes and shelves. This high degree of contact causes damage to the surface by scratching, breakage, cracking, or other defects. Such abrasions are especially visible on dark products like green or brown glass or plastic bottles used in the beverage industry. However, these abrasions are also observed in uncolored bottles.
Every time a container is reused it is exposed to the opportunity to scratch or further scratch the surface. This especially occurs on bottles and scratches or scuff marks generally occur in the shoulder and the bottom area in the form of rings. Such scuffs or abrasions are not only undesirable purely from an aesthetic point of view but they can be undesirable from an economic point of view because they can negatively influence a customer's buying decision. A customer may choose not to purchase a product having a highly scuffed or aesthetically unpleasing container. As such, abrasions can reduce the maximum number of reuse or refillings per container.
The use of scratch or scuff masking agents on glass containers is known. Such masking agents desirably mask scuffs, and exhibit acceptable surface properties and durability. Desirable scuff-masking agents are water-resistant, durable, non-toxic, and removable in alkaline bottle washing operations. Beyond these properties, the scuff-masking agents exhibit good abrasion-masking properties, dry well, are not sticky, remain on the container after washing or alternatively are easily removed during washing, are resistant to moisture, and meet food safety requirements. Coating systems that rely on heat to cure or dry an applied coating are not effective on lines where the glass bottles are cool. Heating may be impossible because raising the temperature of the product to be placed in the container may be detrimental to the organoleptic properties of the product. Even if heating is possible for the product contained in the glass, an additional drying step may be impossible since the coating process usually proceeds automatically. Generally no time exists for extensive drying steps including heat.
Protective coatings are applied to glass containers during manufacture in either a hot end process and/or cold end process. In a cold end process, moisture on the bottles such as from condensation can adversely impact such systems, and with some coatings, long cure times due to moisture (condensation) can adversely impact a coating system. Many existing products show poor or unsatisfactory performance when applied to wet bottles, or on cold bottles which become wet due to condensation. These include, but are not limited to, filling of glass bottles or containers with cold stuffs, typically cold liquids, such as sparkling liquids, e.g. sparkling water, sodas, juice, beer, and the like. This poor performance is attributed to the fact that the condensation water on the outside of the container contributes to further dilution of the masking product resulting in a ‘rinsing off’ of the applied coating. Such rinsing results in no coating remaining on the container surface.
Some coatings are undesirable due to their hygroscopicity. These coatings become sticky and attract dust which only serves to further deteriorate the appearance of the surface. It is against this background that the present disclosure is made.